refactoring and fixes

tagstudio/src/core/query_lang/ast.py

@@ -84,24 +84,24 @@ T = TypeVar("T")
 class BaseVisitor(ABC, Generic[T]):
     def visit(self, node: AST) -> T:
         return {
-            ANDList: self.visit_ANDList,
-            ORList: self.visit_ORList,
-            Constraint: self.visit_Constraint,
-            Property: self.visit_Property,
+            ANDList: self.visit_and_list,
+            ORList: self.visit_or_list,
+            Constraint: self.visit_constraint,
+            Property: self.visit_property,
         }[type(node)](node)
 
     @abstractmethod
-    def visit_ANDList(self, node: ANDList) -> T:  # noqa: N802
+    def visit_and_list(self, node: ANDList) -> T:
         raise NotImplementedError()
 
     @abstractmethod
-    def visit_ORList(self, node: ORList) -> T:  # noqa: N802
+    def visit_or_list(self, node: ORList) -> T:
         raise NotImplementedError()
 
     @abstractmethod
-    def visit_Constraint(self, node: Constraint) -> T:  # noqa: N802
+    def visit_constraint(self, node: Constraint) -> T:
         raise NotImplementedError()
 
     @abstractmethod
-    def visit_Property(self, node: Property) -> T:  # noqa: N802
+    def visit_property(self, node: Property) -> T:
         raise NotImplementedError()

tagstudio/src/core/query_lang/parser.py

@@ -18,6 +18,8 @@ class Parser:
         self.next_token = self.tokenizer.get_next_token()
 
     def parse(self) -> AST:
+        if self.next_token.type == TokenType.EOF:
+            return ORList([])
         out = self.__or_list()
         if self.next_token.type != TokenType.EOF:
             raise ParsingError(self.next_token.start, self.next_token.end, "Syntax Error")

tagstudio/src/core/query_lang/tokenizer.py

@@ -58,7 +58,7 @@ class Tokenizer:
     def __init__(self, text: str) -> None:
         self.text = text
         self.pos = 0
-        self.current_char = self.text[self.pos]
+        self.current_char = self.text[self.pos] if len(text) > 0 else None
 
     def get_next_token(self) -> Token:
         self.__skip_whitespace()
@@ -143,9 +143,7 @@ class Tokenizer:
             self.current_char = None
 
     def __skip_whitespace(self) -> None:
-        if self.current_char is None:
-            return
-        while self.current_char.isspace():
+        while self.current_char is not None and self.current_char.isspace():
             self.__advance()